A type of electrical terminal strip which is being used to an increasing extent comprises a continuously molded plastic strip made up of spaced apart tubular insulators which are connected to each other by integral plastic connecting strips. The metallic terminals are inserted into the insulators and at the time of crimping of the leading terminal of the strip onto a wire, the terminal being crimped is severed from the adjoining connecting strips. Terminal strip of this type is used with crimping machines of the type comprising a crimping press and an applicator having a feeding means for feeding the strip to the crimping zone which is between the crimping anvil and the crimping die. During each crimping cycle, the leading terminal is crimped onto a wire and at the same time, the leading terminal is severed from the carrier strip means which may be a separate carrier strip or individual carrier strip connecting sections as described above.
It has been found that where the terminal strip comprises a continuously molded plastic strip of spaced apart insulators and intervening connecting sections, the behavior of the strip is not always predictable and a feeding problem is frequently encountered. The nature of the feeding problem encountered can be appreciated if it is recalled that when the terminal strip is fed, it is necessary to position the leading terminal of the strip between the crimping die and the crimping anvil and in order to do so, the leading terminal must enter the crimping zone at a level above the upper surface of the crimping anvil. If the leading end of the strip is below this upper surface, the leading terminal of the strip or the carrier strip itself will engage the side of the anvil and misfeeding will result. This problem is not ordinarily encountered with terminal strip in which the carrier strip is a metallic strip, but it has been observed with plastic carrier strip. The physical properties of plastic materials, insofar as they relate to the feeding of terminal strip in an applicator, are somewhat variable, and some plastic strips may have less rigidity than others. It has, in fact, been observed that carrier strips of different colors sometimes have seemingly different physical characteristics in this respect indicating that the coloring material added to the polymer at the time of molding affects the properties of the finished strip.
It is impractical to attempt to control the physical properties of the plastic strip in order to avoid the problem discussed above, and the present invention is directed to the achievement of an improved crimping apparatus having features which prevent any misfeeding of the terminal strip as a result of variations in the physical properties of the plastic strip.